During the operation of vehicles with electric motors, it appears to be possible in principle to bring the vehicle from a standstill to top speed without changing a gear ratio in the drive train. However, it has been found that in this case, the electric motor cannot be operated in an optimal operating point.
Therefore, it is already known to use, for example, a two-speed transmission in a drive train for an electric motor in a motor vehicle. A shift may be made between a first gear ratio for starting and driving at a low vehicle speed, for example, and a second gear ratio for faster driving, for example.
The publication DE 10 2010 024 147 A1 provides this type of two-speed transmission and a corresponding method for controlling the two-speed transmission. The two-speed transmission may transmit the drive torque of the electric motor to an output gearwheel, on the one hand with gear step-down via a planetary gear section, and on the other hand directly, without gear step-up. It is thus possible to operate the electric motor in an operating point that is adapted at least to the speed range.